Patients with neck pain often also have pain in the upper limb. In fact, they may present initially with upper limb pain and often, irritation of the brachial plexus is considered in the absence of complaints of neck pain.
Whether the patient’s primary complaints are in the shoulder, arm, elbow, forearm, wrist, hand or fingers, cervical nerve root irritation must be considered.
It is important to be familiar with the anatomy of the brachial plexus so that you can decipher the nerve roots that may be involved or irritated.
The brachial plexus is formed from the contributions from the cervical nerve roots in the neck.
Roots (5 roots) in the neck: Anterior primary rami of the C5 – T1 nerve roots. A pre-fixed plexus has contributions from C4 and a post-fixed plexus has contributions from T2.
Dorsal scapular nerve arises from the anterior primary ramus of C5 nerve root. It supplies the rhomboideus major and minor, and also the levator scapulae muscle.
Other nerves arriving from the anterior primary ramus of C5 includes nerve to the subclavius and also twigs to the scalenes.
Long thoracic nerve arises from the anterior primary rami of C5, C6 and C7 nerve roots to supply the serratus anterior.
Trunks (3 Trunks), above the clavicle:
Upper trunk: Combination of anterior primary rami of C5 and C6 roots. Suprascapular nerve arises from the upper trunk to supply the supraspinatus and infraspinatus muscles.
Middle trunk: Anterior primary ramus of C7 root.
Lower trunk: Combination of anterior primary rami of C8 and T1 roots.
Divisions (6 divisions), behind the clavicle: All trunks divide into anterior and posterior divisions.
Cords (three cords), in the axilla surrounding the axillary artery:
Lateral cord: Formed from the anterior divisions of the upper trunk and middle trunk.
Medial cord: From the anterior division of the lower trunk.
Posterior cord: Formed from the posterior divisions of the upper, middle and lower trunks
Peripheral nerves from the lateral cord (3):
Lateral head of the median nerve
Lateral pectoral nerve
Musculocutaneous nerve
Nerves from the posterior cord (5):
Upper subscapular nerve
Lower subscapular nerve
Nerve to the Latissimus dorsi
Circumflex nerve (axillary nerve)
Radial nerve
Nerves from the medial cord (5):
Medial pectoral nerve
Medial cutaneous nerve of the arm
Medial cutaneous nerve of the forearm
Medial head of the median nerve
Ulnar nerve